SGLT2-inhibition increases total, LDL, and HDL cholesterol and lowers triglycerides: Meta-analyses of 60 randomized trials, overall and by dose, ethnicity, and drug type

BACKGROUND AND AIMS

Sodium glucose co-transporter 2 (SGLT2)-inhibitors were developed as glucose-lowering drugs. Surprisingly, SGLT2-inhibitors also reduced risk of cardiovascular disease. The impact of SGLT2-inhibitors on lipids and lipoproteins is unclear, but an effect might contribute to the observed lower cardiovascular risk. We conducted a meta-analysis to examine this, overall and by dose, ethnicity, and drug type.

METHODS

PubMed, EMBASE and Web of Science were searched for randomized controlled trials examining all available SGLT2-inhibitors. Studies with available lipid measurements were included. Quantitative data synthesis was performed using random and fixed effects models.

RESULTS

We identified 60 randomized trials, including 147,130 individuals. Overall, using random effects models, SGLT2-inhibitor treatment increased total cholesterol by 0.09 mmol/L (95% CI: 0.06, 0.13), low-density lipoprotein (LDL) cholesterol by 0.08 mmol/L (0.05, 0.10), and high-density lipoprotein (HDL) cholesterol by 0.06 mmol/L (0.05, 0.07), while it reduced triglycerides by 0.10 mmol/L (0.06, 0.14). Fixed effects estimates were similar but with smaller effect sizes for HDL cholesterol and triglycerides. For higher SGLT2-inhibitor doses, there was a nominally higher non-significant effect on lipids and lipoproteins. In Asian compared to non-Asian populations, a slightly larger increase in HDL cholesterol and a decrease in triglycerides were observed, but with similar results for total and LDL cholesterol. Treatment effects on lipids and lipoproteins were generally robust across different SGLT2-inhibitor drugs.

CONCLUSION

In meta-analyses, SGLT2-inhibition increased total, LDL, and HDL cholesterol and decreased triglycerides. Effect sizes varied slightly by drug dose and ethnicity but were generally robust by drug type.

Synthesis and biological evaluation of glucagon-like peptide-1 analogs with the C-terminal helix 3 of albumin-binding domain 3

Based on peptide 6 (Ser⁸-GLP-1 [7-35]-GVKALIDEILAA-NH₂; GVKALI-DEILAA is the C-terminal helix 3 of albumin-binding domain 3 of protein G from bacterial Streptococcal G strain 148 [G148-ABD3]), a series of its analogs (compounds 0-VI: Aib⁸-GLP-1 [7-35]-linkers-GVKALIDEILAA-NH₂) were designed and synthesized using microwave-assisted solid-phase synthesis. First, to monitor the reaction process and reduce potential risks, the synthesis process of compounds 0-VI was divided into three stages. Next, to explore the effect of these linkers on their albumin-binding rates, albumin-binding assays were performed. Finally, to evaluate their biological activities in vitro and in vivo, receptor potency, surface plasmon resonance (SPR), weight-loss, and glucose-lowering assays were carried out. These results indicated the linkers of different polarities between Aib⁸-GLP-1 (7-35) and the C-terminal helix 3 of ABD3 can significantly affect the albumin-binding rate of the C-terminal helix 3 of ABD3. And compound IV had the highest albumin-binding rates, weight-loss, and glucose-lowering effects among them.

Renal outcomes associated with glucose-lowering agents: Systematic review and meta-analysis of randomized outcome trials

Although the clinical questions of the recent glucose-lowering trials are principally oriented towards preventing macrovascular events, an updated review regarding renal outcome prevention is lacking. We assessed the impact of different antihyperglycemic classes on kidney damage progression. A systematic review and meta-analysis was performed by searching PubMed, Cochrane Collaboration Library, Medline, and previous overviews through June 2021 (any language) for earlier and contemporary glucose-lowering trials, including patients with, but not limited to, type 2 diabetes mellitus vs. placebo or less intense treatment. Incidences of kidney function worsening and macroalbuminuria development was extracted, and risk ratios and 95% confidence intervals (CI) under the random-effects model were calculated. The association between outcome reductions and glycohemoglobin (HBA1c) reductions was investigated through the meta-regression analyses. Among 27 eligible trials (n = 198,532 patients) an averaged HBA1c reduction of 0.6 ± 0.3% was followed by a reduction of 17% (95% CI, 8-25%) in worsening of kidney function, and of 25% (95% CI, 19-32%) in macroalbuminuria. Analog of human glucagon-like peptide 1 (GLP1)-agonists, and sodium-glucose cotransporter (SGLT2)-inhibitors, considered separately, compared with placebo, were associated with a significant reduction of both renal outcomes, at variance with dipeptidyl peptidase 4 (DPP4)-inhibitors, where no outcome change was observed. Logarithmic risk ratios of macroalbuminuria were related to HBA1c reductions, in contrast to the worsening of kidney function related to systolic blood pressure reduction. Worsening of kidney function and macroalbuminuria development were reduced following glucose-lowering. GLP1 agonists and SGLPT2 inhibitors were associated with protection against both outcomes, while DPP4 inhibitors do not provide renal protection.

Design, synthesis, and biological evaluation of novel dual FFA1 and PPARδ agonists possessing phenoxyacetic acid scaffold

The free fatty acid receptor 1 (FFA1/GPR40) and peroxisome proliferator-activated receptor δ (PPARδ) have been widely considered as promising targets for type 2 diabetes mellitus (T2DM) due to their respective roles in promoting insulin secretion and improving insulin sensitivity. Hence, the dual FFA1/PPARδ agonists may exert synergistic effects by simultaneously activating FFA1 and PPARδ. The present study performed systematic exploration around previously reported FFA1 agonist 2-(2-fluoro-4-((2'-methyl-4'-(3-(methylsulfonyl)propoxy)-[1,1'-biphenyl]-3-yl)methoxy)phenoxy)acetic acid (lead compound), leading to the identification of a novel dual FFA1/PPARδ agonist 2-(2-fluoro-4-((3-(6-methoxynaphthalen-2-yl)benzyl)oxy)phenoxy)acetic acid (the optimal compound), which displayed high selectivity over PPARα and PPARγ. In addition, the docking study provided us with detailed binding modes of the optimal compound in FFA1 and PPARδ. Furthermore, the optimal compound exhibited greater glucose-lowering effects than lead compound, which might attribute to its synergistic effects by simultaneously modulating insulin secretion and resistance. Moreover, the optimal compound has an acceptable safety profile in the acute toxicity study at a high dose of 500 mg/kg Therefore, our results provided a novel dual FFA1/PPARδ agonist with excellent glucose-lowering effects in vivo.

Design, synthesis and biological evaluation of double fatty chain-modified glucagon-like peptide-1 conjugates

Twelve double fatty chains and Aib⁸-Arg³⁴-GLP-1 (7-37) were designed and obtained by microwave-assisted solid-phase synthesis. Then, twelve conjugates of Aib⁸-Arg³⁴-GLP-1 (7-37) were synthesized in 1% triethylamine aqueous solution. Conjugates 2, 3, 6, 7, 10 and 11 showed better GLP-1 receptor activation potency than semaglutide. However, conjugates 2, 6 and 10 showed slightly worse glucose-lowering effects in vivo than semaglutide but better effects than conjugates 3, 7 and 11. The CD spectra of conjugates 2, 6 and 10 indicated that they had the same secondary structure as liraglutide and semaglutide. The receptor affinity results for conjugates 2, 6 and 10 measured by SPR (surface plasmon resonance) showed that conjugate 2 had higher receptor affinity than conjugates 6 and 10. In addition, albumin binding assays indicated that double fatty acid chains had obvious synergistic effects compared with single fatty acid chains. In conclusion, the structure-activity relationship of different side chains was summarized and one candidate, conjugate 2, was screened.

Legacy effect of intensive glucose control on major adverse cardiovascular outcome: Systematic review and meta-analyses of trials according to different scenarios

BACKGROUND

Early and intensive glycaemic control provides long-term protection against the development of microvascular complications, a phenomenon defined legacy effect. Whether a legacy effect of high glucose exists also on macrovascular endpoints is uncertain.

METHODS AND FINDINGS

We performed a systematic review of both randomized clinical trials (RCT)s and observational studies pertinent to the research question. We searched PubMed, Embase, Scopus and the Cochrane database up to January 31th 2020. Eligibility criteria for RCTs were: 1 - efficacy assessment of intensive glucose lowering treatment vs a less-stringent/conventional treatment; 2 - the inclusion of a post-active phase, observational follow-up; 3 - enrolment of patients with T1DM, pre-diabetes, and T2DM; and 4 - data report on major adverse cardiovascular events (MACE) incidence, which was the primary endpoint of this meta-analysis. We performed multiple meta-analyses of the available RCTs according to different scenarios considering the type of diabetes, diabetes duration, the presence of previous cardiovascular events, follow-up extension, and the incidence of MACE recorded only during the observational, post-active phase of the trials. Results from observational studies reporting the association between HbA1c levels during the first year after diabetes diagnosis and subsequent MACE incidence were also collected and are reported narratively. We included data from 7 RCTs and 40,346 patients. The intensive glucose-lowering approach significantly decrease the incidence of MACE compared with conventional treatment (OR 0.86, CI 0.77-0.96; p = 0.007) when considering all the available studies, with a more consistent effect (OR 0.73, CI 0.56-0.94; p = 0.01) in the case of RCTs enrolling patients with diabetes duration <10 years, and an even more pronounced protection (OR 0.64, 48 CI 0.48, 0.86; p = 0.003) when analysing only RCTs enrolling patients without previous cardiovascular events at baseline. Considering only RCTs with a post-trial follow-up >10 years also yielded a relevant beneficial effect of the intensive approach (OR 0.71, CI 0.57, 0.88; p = 0.002). On the other hand, no effect was observed (OR 0.99, CI 0.92, 1.06; p = 0.81) when considering only the events recorded during the post-active, observational phases of the trials. Observational studies showed that HbA1c values >6.5% or 7% during the first year of diabetes diagnosis are associated with a higher incidence of late MACE with increased risk ranging from 19 up to 64%, according to the different study design and HbA1c stratification.

CONCLUSIONS

These results support the recommendation regarding glucose-lowering treatment intensification in order to decrease the probability of having a macrovascular event in patients with short diabetes duration, no prevalent cardiovascular diseases, and long life-expectancy. On the other side, data from RCTs do not support the existence of a protective legacy effect on the macrovasculature beyond the period of intensive glycaemic treatment.

Two-hundred-liter scale fermentation, purification of recombinant human fibroblast growth factor-21, and its anti-diabetic effects on ob/ob mice

Fibroblast growth factor-21 (FGF-21) is a potential cytokine for type II diabetes mellitus. This study aimed to optimize recombinant human FGF-21 (rhFGF-21) production in Escherichia coli BL21 (DE3) employing high cell density fermentation at a 200-L scale and pilot-scale purification. FGF-21 was eventually expressed in E. coli BL21 (DE3) using human FGF-21 synthetic DNA sequence via the introduction of vector pET-3c; the product is used as seed strain during the fermentation of rhFGF-21. Fermentation of rhFGF-21 was performed in a 30-L and 200-L fermenters. rhFGF-21 was primarily expressed in the form of inclusion bodies after IPTG induction. At the 200-L scale, the bacterial production and expression levels of rhFGF-21 were 38.8 ± 0.6 g/L and 30.9 ± 0.7%, respectively. Additionally, the high purification (98%) of rhFGF-21 was tested with HPLC analysis and reducing & non-reducing SDS-PAGE analysis. The final yield of purified rhFGF-21 was 71.1 ± 13.9 mg/L. The activity of rhFGF-21 stock solution reached at 68.67 ± 8.74 IU/mg. Blood glucose controlling and insulin sensitization were improved with treatment of rhFGF-21 in type II diabetic ob/ob mice. Our results showed that the relatively stable and time-saving pilot-scale production process was successfully established, providing an efficient and cost-effective strategy for large-scale and industrial production of rhFGF-21.

The actions of SGLT2 inhibitors on metabolism, renal function and blood pressure

Inhibition of the sodium-glucose cotransporter (SGLT) 2 in the proximal tubule of the kidney has a broad range of effects on renal function and plasma volume homeostasis, as well as on adiposity and energy metabolism across the entire body. SGLT2 inhibitors are chiefly used in type 2 diabetes for glucose control, achieving reductions in HbA_1c of 7-10 mmol/mol (0.6-0.9%) when compared with placebo. This glucose-lowering activity is proportional to the ambient glucose concentration and glomerular filtration of this glucose, so may be greater in those with poor glycaemic control and/or hyperfiltration at baseline. Equally, the glucose-lowering effects of SGLT2 inhibitors are attenuated in individuals without diabetes and those with a reduced eGFR. However, unlike the glucose-lowering effects of SGLT2 inhibitors, the spill-over of sodium and glucose beyond the proximal nephron following SGLT2 inhibition triggers dynamic and reversible realignment of energy metabolism, renal filtration and plasma volume without relying on losses into the urine. In addition, these processes are observed in the absence of significant glucosuria or ongoing natriuresis. In the long term, the resetting of energy/salt/water physiology following SGLT2 inhibition has an impact, not only on adiposity, renal function and blood pressure control, but also on the health and survival of patients with type 2 diabetes. A better understanding of the precise biology underlying the acute actions of SGLT2 inhibitors in the kidney and how they are communicated to the rest of the body will likely lead to improved therapeutics that augment similar pathways in individuals with, or even without, diabetes to achieve additional benefits.

Predictors for the Treatment Effect of Sodium Glucose Co-transporter 2 Inhibitors in Patients with Type 2 Diabetes Mellitus

INTRODUCTION

Predictors for the effect of sodium glucose co-transporter 2 (SGLT2) inhibitors at lowering hemoglobin A1c (HbA1c) levels in type 2 diabetes mellitus patients remain unclear. We therefore aimed to elucidate these predictors in type 2 diabetes patients after 3 months of SGLT2 treatment.

METHODS

A total of 302 consecutive type 2 diabetes patients who had been treated with SGLT2 inhibitors as monotherapy or add-on therapy to existing antidiabetic treatments were enrolled retrospectively. After excluding 27 patients whose HbA1c levels could not be evaluated 3 months after treatment, the glucose-lowering effects of SGLT2 inhibitors were assessed in 275 patients by measuring HbA1c levels before and 3 months after treatment. The predictors for changes in HbA1c levels after 3 months of treatment were evaluated.

RESULTS

SGLT2 inhibitor treatment for 3 months decreased HbA1c levels from 7.8 ± 1.2% to 7.4 ± 1.0% (p < 0.0001). A multiple regression analysis showed that the independent determinants for SGLT2 inhibitor treatment effect included decreased HbA1c levels after 1 month of treatment, high baseline HbA1c levels, and a high estimated glomerular filtration rate (eGFR).

CONCLUSION

We show that type 2 diabetes patients who received the greatest glucose-lowering effect with SGLT2 inhibitor treatment were those with preserved renal function (high baseline eGFR) and high baseline HbA1c levels. Moreover, SGLT2 inhibitor treatment efficacy could be predicted by the patients' initial response to treatment.